Condensing boilers offer tangible benefits by reducing carbon dioxide emissions to help combat global warming, and improve household efficiency thus reducing fuel bills.
Condensing boilers work on the principle of recovering as much as possible of the waste heat which is normally rejected to the atmosphere from the flue of a conventional (non-condensing) boiler.
This is accomplished by using an extra-large heat exchanger or sometimes two heat exchangers within the boiler which maximises heat transfer from the burner as well as recovering useful heat which would normally be lost with the flue gases.
When in condensing mode (for condensing boilers do not condense all the time) the flue gases give up their ‘latent heat’ which is then recovered by the heat exchanger within the boiler. As a result the temperature of the gases exiting the flue of a condensing boiler is typically 50-60°C compared with 120-180°C in a current non-condensing boiler. At the same time an amount of water or ‘condensate’ is produced.
A condensing boiler will always have a better operating efficiency than a conventional non-condensing one, due to its larger and more efficient heat exchanger.The benefits of condensing boilers are therefore quite clear.
95.8kb), produced by Energy Efficiency Best Practice in Housing provides concise and well written information about condensing boilers.
